4 surprisingly simple ways to lengthen your life

We all know that eating our fruits and veggies, keeping fit, getting enough sleep and not smoking will help us live longer – upwards of over 10 years longer. But there are some other simple ways you can add years to your life. Among them:

1. Smile big and wide.

Smiling big and wide is related to living longer, according to research published in the journal Psychological Science. These researchers looked at professional baseball players' photos and compared the lifespan of players with big smiles, no smiles and partial smiles.

Even after controlling for factors that are related to longevity such as education level and marital status, bigger smiles were still related to a longer life. The researchers found that the biggest smilers lived to an average of almost 80 years, while their straight-faced teammates reached only an average of 73 years. Why? In part because smiling builds your immune system and improves your mood and stress levels. And as an added bonus, smiling makes you more attractive.

[See: What Keeps You Young?]

2. Floss daily.

Although there is some debate, it appears that daily flossing decreases low-grade inflammation, which increases the risk of early heart attack and stroke. Flossing also reduces gingivitis (a gum disease that causes irritation, redness and swelling in the part of your gum around the base of your teeth) compared to brushing your teeth alone, according to a review published in the Cochrane Database of Systematic Reviews. That's probably because flossing not only gets rid of food trapped between your teeth, but it also removes the bacteria that forms before it has a chance to harden into plaque – something your toothbrush cannot do.

The American Dental Association recommends flossing at least once a day to get rid of plaque in areas between the teeth that are difficult or impossible to reach with a toothbrush. As long as you floss once a day, it doesn't matter when. Unfortunately, only 3 out of 10 Americans floss at least once a day, and over 32 percent never floss, according to data from the National Health and Nutrition Examination Survey.

3. Improve your posture.

Turns out that mom and dad were right: Sitting up straight is important. Your body is designed so that your heart and lungs work better when you have good posture since it reduces the excessive force that muscles and joints need to absorb. A long-term University of London study of about 4,000 men found that those who lost height as they aged – in other words, their posture worsened over time – were more likely to die prematurely from cardiovascular or respiratory conditions than their counterparts who maintained good posture. And, slouchier postures cause neck and back pain and makes you look less confident and feel less competent.

To have good posture when sitting down, keep your chin parallel to the floor; your shoulders, hips and knees at even heights; and your knees and feet pointing straight ahead.

[See: 5 Bodyweight Exercises to Fix Your Posture.]

4. Wash your hands.

Washing your hands is a simple way to longer life. In fact, hygiene is a main factor in why our life expectancy has almost doubled in the last 150 years. That's because hand-washing kills bacteria and keeps us healthier. Improper hand-washing accounts for nearly half of all foodborne illness in the U.S. In one study, almost half of the participants had bacteria on their hands of potential – brace yourself – fecal origin. But rinsing with water cut that number in half, and adding soap left just 8 percent of people's hands dirty.

[See: Do You Really Need to Cover the Toilet Seat With Paper?]

Although two-thirds of adults typically wash their hands in a public restroom with soap and water, few people scrub for the recommended 20 seconds. To avoid being another dirty statistic, wet your hands under clean, running water and apply soap. Then, lather your hands – including the backs of your hands, between fingers and under nails – for at least 20 seconds. Rinse your hands with water and dry them using a towel or allow them to air dry.